GASTEROPODA OF THE EVUCENE MARLS. 935 
extent as above. The position of the extremely narrow slit is marked by 
an elevated line on each margin. 
This shell differs from L. perlata in the form of the volution, wanting 
the flattening of the upper surface, and from L. gigantea in its more spread- 
ing form and greater apical angle. 
Formation and locality: Inthe upper layers of the Upper Green Marls, 
at Shark River, New Jersey. Collection of the Am. Mus. Nat. Hist. 
TREMATOFUSUS, n. gen. 
Shell short fusiform, with rounded, ventricose body volution, and 
slender, straight anterior beak and narrow canal, and smooth columella. 
Volutions ornamented by fine spiral lines, and on the upper part with a 
series of small tubular nodes, which appear to have formed a series of per- 
forations around the periphery of the volution similar to those of Polytremaria 
D’Orb. from the Carboniferous formation. Type 7. venustus. 
I propose the above generic, name for a species of shell for whien I can 
find no established generic group. The specimens of the only species known 
are internal casts, and their matrices in green marl; but all the features 
of the shell are easily obtainable from those in hand. The shell quite 
closely resembles a high spired form of Polytremaria, provided with a mod- 
erately long, straight, and slender beak, which in the typical species is about 
equal to the height of the spire. Except for the perforated nodes or sub- 
spines, which rise quite abruptly from the body volution, the shell would 
form a rather short, wide-bodied Fusus, with a rounded and abruptly spread- 
ing body volution. Of course, as I have only the casts and matrix to judge 
from, I can not positively affirm that these nodes or spines were really per- 
forated during life—still they present every reasonable evidence of having 
been so formed. The shells have been extremely thin in texture. 
TREMATOFUSUS VENUSTUS, Nn. sp. 
Plate xxxv, Figs. 5-7. 
Shell of moderate size, with an elevated, rather slender spire and very 
rapidly increasing body volution, and witha slender, straight anterior canal, 
equaling in length the height of the spire. Upper volutions four in num- 
